In the most recent quarter, the retailer's same-store sales sales grew 4.3%, and total sales rose 11% to .9 billion.

We went to a Dollar General store in Richmond, Virginia, to find out what makes it so successful." data-src="" role="presentation" src="//static-entertainment-neu-s-msn-com.akamaized.net/sc/9b/e151e5.gif" title="Dollar General is opening 900 stores this year, remodeling 1,000 locations, and relocating 100 store... The 21-year-old student told Business Insider that he has built a business selling nootropic supplements, primarily by marketing on social media.

Codd's research on relational database design, which led in 1977 to the formation of what became Oracle.

Oracle became a successful database vendor to mid- and low-range systems, competing with Sybase and Microsoft SQL Server, which led to Ellison being listed by Forbes as one of the richest men in the world.

In addition to his work at Oracle, Ellison has had success in yachting, through Oracle Team USA.

Ellison left the University of Illinois at Urbana–Champaign after his second year, not taking his final exams, because his adoptive mother had just died.

After spending a summer in Northern California, he attended the University of Chicago for one term, where he first encountered computer design. During the 1970s, after a brief stint at Amdahl Corporation, Ellison began working for Ampex Corporation.

He uses the money to pay his college tuition and living expenses in downtown Los Angeles. "I realized that if I wanted to be a successful businessman, I needed to start now," said Kozlovski.

"I thought I'll learn a lot more from actually running a business while in business school than waiting four years to get started." But running a business while attending school isn't easy.